Lock



Nov. 11, 1924. 7 1,515,252

' W. R. HOYT LOCK Filed Aug. 14, 1923 Gum wags Patented Nev. 11, 3224 WILLIAM R. HOYT, OF STAIvIFOR/D, CONNECTICUT, ASSIGNOR TO THE YALE & TO'WNE MANUFACTURING CUMPANY, 0F STAMFORD, CONNECTICUT.

LOCK.

Application filed August 14, 1923. Serial No. 657,280.

T 0 e32 whom it may concern:

Be it known that I, WILLIAM R. HoY'r, a citizen of the United States, and a resident of Stamford, in the county of F airfield and State of Connecticut, have invented certain new and useful Improvements in Locks; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in looks and more particularly to those of the rim type employing a cylinder lock structure,one object of the invention being to provide simple means whereby the bolt operating cam will be effectually blocked in the event that attempt be made to wrench the cylinder look from its connection with the back plate of the rim lock casing.

Vith this object in View, the invention consists in certain novel features of construction as will be hereinafter described and pointed out in the claims.

In the accompanying drawing,

Figure 1 is a face view of a rim look back plate showing an application of my invention.

Figure 2 is a sectional view on the line 2-2 of Figure 1.

Figure 8 is a sectional view on the line 38 of Figure 1.

Figure 4 is a detail perspective view of the blocking device, and

Figure 5 is a view illustrating the blocking position of the blocking device.

The back plate of a rim lock structure is shown at 1 and is provided with a mounting for the hub or roll back member 2 of a roll back Or bolt operating cam 3. In proximity to the mounting of the roll back cam, the plate 1 is provided with a plurality of holes 4, any two of which may be utilized for the accommodation of bolts which secure a cylinder look (not shown) in place. The holes 4 are made cylindrical and slightly larger in diameter than that of the heads of said bolts and in the holes 4 through which the bolts are passed, thimbles 5 are located and these thimbles are provided each with a finger 6 and also slightly flanged, as shown at 7, Figures 2 and 3. The thimble 5 with its finger 6 constitute a blocking device to render the bolt operating cam inoperable in the event of the unauthorized loosening of the connection of the cylinder lock with the back plate. The cylinder securing bolts will have heads of such size that they will seat within the thimble portions 5 of the blocking devices and'hold the finger portions of said devices normally out of the path of movement of the bolt operating cam.

One thimble or blocking device 5 will sufiice for effecting the blocking of the bolt operating member. Two such blocking devices Will be provided however, as where the lock is used on a right hand door, the upper pair of screws and one blocking device will be used, while for a left hand door, the other pair of screws will be used with the other blocking device. Thus it will be seen that two blocking devices must be present on the cover plate but only one is used in each application of the lock to the door.

WVith my improvements, should an attempt be made to forcibly remove the lock cylinder,the head of the securing bolt will operate to strip the thimble portion of the blocking device through the larger hole 4 in the back plate (the flange 7 of the thimbie giving away) and the finger portion of said device will be tilted so as to become disposed in the path of movement of the bolt operating cam, thus blocking the latter and preventing its effective operation.

Having fully described my invention What I claim as new and desire to secure by Letters-Patent, is:

1. The combination with the back plate of a rim lock structure having a hole for a securing bolt of a cylinder lock and a bolt operating cam mounted on said back plate, of a cam blocking member located in said bolt hole in position to receive the head of the securing bolt and to be held thereby normally out of the path of the bolt operating cam and to be moved into the path of said cam upon the application of excessive strain on the securing bolt.

2. The combination with the back plate of a rim lock structure having a hole for the accommodation of a bolt for securing a cylinder lock in place and abolt operating cam mounted on said back plate, of a blocking device for the bolt operating cam, said blocking device comprising a thimble located in the hole in the back plate and affording a seat for the head of the securing bolt and a finger normally out of the In testimony whereof, I have signed this path 0-1 the bolt operating cam, whereby specification in the presence of two sub- 1Q excessive strain applied to the securing bolt scribing Witnesses.

will 0 erate to stri the thimble throu h the 7, U v

hole the back plate and dense said ii'ng'er WILLIAM? to become dispo'sed'in the path of the bolt Witnesses:

operating cam to block the effective throw A. DOUGLAS DALTON,

of the latter. CHARLES A. BERRY. 

